Idiopathic pneumonia syndrome

Idiopathic pneumonia syndrome (IPS) refers to diffuse lung injury which can occur following haematopeotic stem cell transplantation where neither an infectious nor non-infectious aetiology can be found.

The incidence of IPS is thought to be around 12% following haematopoetic stem cell transplantation. 

Clinical presentation can vary from being asymptomatic to full blown acute respiratory distress syndrome. Its median onset time is around 40-50 days following transplantation, but there is an early peak in the first 14 days, followed by a lower but consistent incidence up to around 80-100 days.

Its aetiology is thought to be multifactorial inclusive of chemoradiotherapeutic insults and graft versus host disease 4. There are two main histopathological patterns

  • interstitial pneumonitis
  • diffuse alveolar damage
Plain radiograph / CT
  • would typically show diffuse airspace and/or intestinal infiltrative opacification 4
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Article information

rID: 29840
System: Chest
Section: Syndromes
Synonyms or Alternate Spellings:
  • Idiopathic pneumonia syndrome (IPS)
  • Idiopathic pneumonia syndrome post bone marrow transplantation
  • Idiopathic pneumonia syndrome following bone marrow transplantation

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